85' ARB by Melissa T. - Scale 1:32 - POB - First Scratch Build

[Melissa T.]

With three kits now under my belt, I decided to throw caution to the wind and attempt my first scratch build.  My father-in-law, WO James H. Flynn, was first mate on board the P-564 an 85' rescue boat operating off the coast of Japanese-occupied Burma in World War II, and I want to build that boat in his honor.  The CBI (China-Burma-India theater, though often more commonly thought of as "Confusion Beyond Imagination") is often overlooked, but these men served under extremely difficult circumstances and played an important role in hastening the end of the overall war in the Pacific.  P-564 was specifically involved in reconnaissance operations of Japanese-held areas and the covert insertion of OSS teams into Burma in the closing months of the war.  She was one of eight such vessels built in mid-1944 by Herreshoff Manufacturing in Bristol, RI.  

 

I was able to obtain a copy of the plans for the 85' ARBs, and from those I was able to make cardboard templates for a false keel and bulkheads.  The plans are in 1:32 scale, so I decided to stick with that in order to keep things as simple as possible.  I've also been able to find key accessories (like the 20mm cannon, etc.) online in 1:32, it was an easy choice.  I am doing POB because that is what I am familiar with from kits.  As I am not interested in learning CAD (again, keeping things simple), I decided to make a fiberboard prototype of the keel and bulkheads both to see if this project is even doable for me, and also so I could get a three-dimensional sense of what the hull actually looks like.  (It has, for example, a fairly pronounced chine, which I'm not sure I would have realized without the fiberboard prototype). I've invested all of $20 in materials so far, so if this is a flop I won't have wasted a lot of money!

 

Here's where things get serious, and where I could use advice from the experts on this forum.  As this is my first scratch build, I am taking this very slowly, step-by-step, and trying to figure things out as I go along.  The next step will be to build this framework in wood.  Should I use plywood, MDF, or something else for the keel and bulkheads?  What wood would be a good idea to use for the actual planking?  Would a scroll saw, or something else, be advisable to cut out the keel and bulkheads?  I'm attaching pictures so you can hopefully see what I'm trying to do and what I've done so far.  Thank you for any advice you all have to offer!

 

[ccoyle]

The book Retribution by Max Hastings chronicles the last year of the Pacific war, including a significant chunk devoted to events in the CBI theater and an analysis of how they fit into the overall Allied plans for defeating Japan. I just finished re-reading it a few weeks ago.

[Jim Lad]

What a good-looking launch melissa - and an obvious one for you to build.  I think the materials are very much a matter of what appeals to you, but I might be tempted to try ply for the hull skin - that's what the original were built from. You can find very thin good quality ply at some aircraft modelling shops. The frame could be anything you have to hand, provided it works well and is stable.

 

I look forward to seeing your progress.

 

John

[Melissa T.]

Thank you John - that is helpful!

[gsdpic]

I am certainly no expert, but this hull shape appears to be a bit similar to the hull shape of the coast guard cutter that I was just looking at the build log for, by @drobinson02199.   You might be able to "plank" at least parts of the hull with large flat sheets of either plywood or styrene instead of individual small planks.  I think John/Jim Lad was suggesting a similar approach when he mentioned using ply.  The build log, linked below, might give you some ideas for how to construct your hull.

Note that kit was designed to allow RC operation and that probably dictated the open frames to allow room for the RC equipment but it may be easier to use solid bulkheads and the large false keel/backbone as you did with your prototype.

 

This looks like an interesting project of an attractive boat, and it has a bit of extra personal meaning for you.   Good luck!

Edited October 27, 2023 by gsdpic

[Melissa T.]

Interesting - thank you Gary!

[Roger Pellett]

 

Tools:  It is possible to cut the keel and bulkheads with an inexpensive coping saw.  If you plan to go this route, buy the saw, a selection  of blades and practice.  A powered scroll saw certainly makes things easier.

 

Wood:  with scratch building it’s a good idea to develop a building plan before you start.  If I were building this I would build it upside down with the tops of the bulkheads attached to the building board.  I would extend the bulkheads to be cut off after the hull is planked.  

 

Plywood construction requires “developable shapes” as the plywood does not like to bend in more than one dimension. So to accurately reproduce the shape you might have to plank the hull.  There is, of course, a “chine log” that defines the chine and provides the landing along the chine for both the bottom and side planking.  Diagonal planking would be an easy way to plank the bottom and would probably replicate actual practice.

 

I would not use either plywood or MDF for the bulkheads.  I would buy ordinary 1in pine at your local lumberyard/ home improvement store; not spruce or fir.  I would Saw it into 1/16” thick strips and use it to build two layered pentagonal shapes for each bulkhead. Stagger the joints.  Then use your poster board bulkheads to draw the finished shape on to each and cut it out. The center (keel) piece can be made from thin plywood. See if you can find 1/8” Baltic Birch.  The Bottom can be diagonally planked with two layers of craft plywood cut into narrow strips. For the side planking I would cut more of your pine into thin planking strips.

 

Roger

[Melissa T.]

Roger - Thank you. This is extremely helpful. I ordered a Dewalt scroll saw today and will take your advice on the wood. I also like the idea of diagonal planking on the bottom, below the chine. All things I would not have thought of on my own!

[Dr PR]

This is an excellent choice for a first scratch build project. The hull doesn't have complex curves and there is not an extreme amount of superstructure or rigging to deal with. The 1:35 scale allows a tremendous amount of detail, and there is a large amount of military tank and vehicle parts and figures available that might be useful. I have see a couple of beautiful 1:35 scale PT moat models.

 

Personally, if you are building out of wood I would use 1/8 inch model aircraft plywood for the frames and keel. This way you would need only a sheet or two of the plywood, and would be working with only one type of material. I like the good quality aircraft plywood because it doesn't split along the grain like some woods tend to do. This is especially true for small thin parts that must be hand shaped a lot.

 

You could use the really thin (1/64") model aircraft plywood for the hull plating - it does bend pretty much like paper. But is is fragile, and it would be easy to poke holes in the thin stuff between bulkheads. I guess planking would be the way to go if you use wood.

 

Another way to build it would be to use styrene for the hull keel, frames and surface. You can cut paper templates and use these to shape the plastic.  You can heat it with a hair dryer to get it to curve in the right places (don't over do it though).

[Melissa T.]

Thank you, Phil.  Follow-on question - where does one procure this model aircraft plywood?  I'm not familiar with it and have never used it.

[Canute]

Check for a local RC aircraft shop. Absent that, try mail order. Tower Hobbies, in Chicagoland, is one shop I know.

[Roger Pellett]

Model plywood is widely available. Stores like Michaels carry it.  It comes in “nominal” fractional thicknesses, from 1/64” to 1/8”.  Nominal  means that it is actually metric thicknesses that are close to fractions.  I believe that there are two grades; the Craft grade material that you are likely to find locally and a higher grade intended for model aircraft and available from specialty RC model aircraft suppliers.  If you use it for the applications that I am suggesting the Craft Grade Material is fine.

 

I suggest that you do need one piece of high class material; the piece for the keel.  Many of the kit build logs report warped keels that require a lot of effort and frustration to correct.  You can find 1/8” Baltic Birch ply at on line woodworking sources.  Try Woodcraft Supply.

 

I personally would not suggest using any sort of plywood for frames.  Plywood is great for it’s intended use; covering flat or developable surfaces, but it’s Achilles heel is its cut edge.  If you need to use any kind of fastener, permanent or temporary, driven into the edge you can separate the laminations.  Styrene, that’s the dark side😆!

 

Roger

[Melissa T.]

Thank you, Roger!

[alross2]

I drew those plans decades ago using the yard drawings.  Here are a couple variations on paint schemes applied to them.  One (white, yellow, orange) is the "clown" scheme applied to boats post-WWII.  The other is the standard Sea Blue (5-S) and Deck Blue (20-G) of the WWII period.  I have the boat manual and quite a few photos of this type and would be happy to attempt to answer any detail questions you might have.  A number of these boats had the USN's MK12 20mm mount in the well deck aft.  That shown on my old drawing is a MK4 mount, which was on the original drawings.

[Melissa T.]

Al - Yes, the plans have your signature, dated 1986.  Also, your depiction of P-564 that you did for us last year hangs proudly on a wall in our office 😊

 

Are the Sea Blue and Deck Blue paints you mention available commercially for modeling?

[alross2]

35 minutes ago, Melissa T. said:

Al - Yes, the plans have your signature, dated 1986.  Also, your depiction of P-564 that you did for us last year hangs proudly on a wall in our office 😊

 

Are the Sea Blue and Deck Blue paints you mention available commercially for modeling?

Yes, they are made by a number of companies, including True North.  Because P564 operated with the OSS, you might want to confirm her paint scheme, as many of the "spook" boats had specific schemes at different times.

[Dr PR]

Roger is right about trying to nail or screw into the edge of plywood. I think it is OK for bulkheads IF you are just going to use glue to fasten the planking. But if you will be using fasteners or treenails solid wood bulkheads will be better.

 

I got my model aircraft plywood at the local hobby shop that had a lot of R.C modeling supplies. Unfortunately, the Internet and big box stores have starved it to death, as they have also done to our local camera shops.

Edited October 30, 2023 by Dr PR

[Melissa T.]

After a lot of consideration and reviewing the various suggestions, I decided to go with 1/8” model aircraft plywood for the keel and bulkheads.  I wanted the simplicity of working with only one kind of wood for this phase of the project, and I’m not worried about splitting on the edges as I won’t be using any nails.

 

I’m glad I invested in the ginormous DeWalt scroll saw, as I don’t think I could have cut this wood with anything else! Next step will be to begin gluing in the bulkheads one by one at (hopefully) perfectly right angles to the keel. Then lots and lots of fairing. So far so good!

 

 

Edited November 19, 2023 by Melissa T.

[KeithAug]

The scroll saw work on the frames looks very tidy. Not an easy skill to master but you seem to have nailed it.

[Melissa T.]

Thanks Keith - Definitely not easy, but I learned that going super slow is (for me) the trick to staying on the line I had drawn on the wood.

[Melissa T.]

Despite an illness followed immediately by the holidays, I’ve been able to make some progress on this boat and have now completed the planking below the chine.  I was able to find and download the 1944 operator’s manual, which is proving to be an invaluable resource.  From it, I learned that the planking on the actual boats was mahogany, and installed completely longitudinally - no diagonal planking.  So that’s how I’m building my model.  Though I know they surely used a different species of mahogany on the actual boats, I still like the idea of making it as authentic as reasonably possible.  I will be working on this hull for quite some time, building up the sides and a considerable amount of filling cracks, sanding and smoothing are all yet to come.  Looking ahead though, I do have a couple of questions:

 

- I have never used an airbrush, but would like to do so for this model.  Can anyone recommend a good one for this project, preferably something under $500?
 

- Can anyone recommend a good primer to apply to this hull when the time comes?

Thank you and Happy New Year to all!

 

 

[ERS Rich]

26 minutes ago, Melissa T. said:

I have never used an airbrush, but would like to do so for this model.  Can anyone recommend a good one for this project, preferably something under $500?
 

- Can anyone recommend a good primer to apply to this hull when the time comes?

Good Morning,

 

Recommend a Paasche Talon, available at Coast Air Brush and shellac.  Good luck and happy new year!

[Melissa T.]

Thank you, Rich!

[Roger Pellett]

Melissa,

 

First, congratulations on the museum display of your Philadelphia model.  Can you tell us where it is located?

 

Air Brush. IMHO it depends what you want to do.  This ranges from spraying paint to engaging in shading and weathering, etc.  I personally am happy if I can just lay down a nice coat of paint and am on my second Badger 350.  Advantages;  inexpensive, robust, easy to clean, user friendly.   Disadvantage, pretty much on/off with nothing in between.  

 

As important is your air source.  I have a compressor/ air tank combination available at any bid box home improvement store; on sale cost about $100.  It’s noisy but provides plenty of air.  These units generate air at 125psi but have an integral regulator to dial outlet pressure down to airbrush pressure.  This is necessary.  Don’t ask me how I know!

 

Roger

 

 

 

 

[Melissa T.]

Roger - Thanks!  My Philadelphia model is at the New York State Military Museum in Saratoga Springs.  I do some volunteer work there, so I offered up the model for the exhibit and they were happy to take me up on it.

 

Thanks for the insights on airbrush painting.  I just want to apply primer when the time comes, and then the appropriate paints for this WWII vessel in the CBI theater.

 

Melissa

[KeithAug]

Melissa,

 

You can pick up some very cheap airbrushes 20 to 30 dollars - they don't last well but will get you through a model or two. The next step up would be something like this https://www.amazon.co.uk/NEO-Gravity-Feed-Action-Airbrush/dp/B004INERK4/ref=asc_df_B004INERK4/?tag=googshopuk-21&linkCode=df0&hvadid=309819440071&hvpos=&hvnetw=g&hvrand=16945460784911821528&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9045827&hvtargid=pla-383095371970&psc=1&mcid=5eee78d457ec3559a64ef69cd18c4973&th=1&psc=1.

 

It will suffice for most straightforward jobs particularly if you are not going for anything too sophisticated in terms of techniques. My advice would be to stick with the more basic models until you decide you want to move up a gear. Best wishes for the new year.

[gsdpic]

Great progress, Melissa.

 

As for the airbrush, to cover large areas and to use thicker paint (like primer) you likely want something with a large needle.  Many airbrushes aimed more at artists have small needle/nozzle and that would take forever to paint your model.  And you might want one with a larger paint cup as well so that you do not have to fill it quite so often.

 

I recently bought one of these: https://www.gaahleri.com/products/gaahleri-airbrush-ghac-swallowtail-barbatos.  That airbrush includes a 0.7mm needle/nozzle, which is considered fairly large.  And it comes with a couple different sized paint cups to choose from.   There is also a "fan cap" available which changes the spray pattern from a circle to a wider, thinner area.  That might be useful for large areas, though I think the fan cap is only usable with the 0.5mm needle/nozzle.  I have only used my new airbrush a couple times, and on much smaller bits, but so far I am pleased with it.  It seems much better built than the cheapo one I had before it.  I find the "trigger action" airbrushes easier to use than the traditional ones with the lever on top of the air brush.  Though I suspect folks doing more artistic work would feel like the traditional lever gives more control, perhaps.

 

I also have a compressor with a tank.  Unlike the ones from the big box stores, it is made specifically for airbrushing.   The one I have is here: https://spraygunner.com/holiday-gift-ideas/tooty-airbrush-compressor-by-no-name-brand/  As Roger said, having some sort of regulator that allows adjusting the air pressure is essential.  You'll want to use lower pressure, down to 10 or 15 PSI, for very thin paint and higher pressure, like 25 to 30 PSI, for thicker paint.  I don't think I have gone above 30 PSI when using an airbrush.  And yes, unless you buy paint specifically made for airbrushes, you will need to thin it.   I found that getting the right consistency of the paint was one of the bigger parts of the air brush learning curve.

 

One caveat to all that I say....I've only used my airbrush when building plastic cars, not on any model ships/boats.

 

[alross2]

I use a single-action Paasche airbrush that I've had for at least 40 years - works great.  For fillers and primers, I use automotive body putty (like Bondo) and rattle can primer surfacers you can get at your local automotive supply house (NAPA, Pep Boys, etc.).  Bondo is the approximate hardness of basswood and sands beautifully.  As a polyester resin, it also acts as an adhesive.  When the cracks are filled, the wood isn't going anywhere.  The automotive primer surfacers are hard-drying and sand well with wet-or-dry sandpaper for an excellent finish.  Avoid the hardware store primers as they are often soft and clog your sandpaper.

[Dr PR]

Melissa,

 

I have a Paasch airbrush set (VL-SET) that I got 20-30 years ago. It has a VL double action airbrush - push the button down to increase/decrease the airflow and forward/back to control the amount of paint. This "double action" allows very good control of the amount of paint you apply, and you can shut off the paint and just use it as an air supply to blow dry the paint. I don't remember what I paid for it back then, but it has been worth the money for all the painting options it allows. I see it for under $80 on Amazon (less the 3 ounce bottle).

 

It came with three needle/nozzle sets for fine (narrow), medium and heavy (wide) paint application. This is good for painting small parts or larger surfaces like hulls.

 

It has a paint cup for small amounts of paint and two bottles (1 and 3 ounce) for larger paint jobs (but not large enough to paint your house if you are in a hurry).

 

****

 

The air compressor and regulator are as important as the airbrush. Be sure you can adjust the pressure to the 20-30 psi range. An air tank on the compressor output is good because it will absorb some of the pressure pulsations from the compressor and collect moisture from the cooling compressed air. Just about anything you can find that meets these requirements will work.

[druxey]

A moisture trap in the air line takes care of condensation. The trick with any airbrush is meticulous almost surgical cleaning after each use!